In many fields of applications, electrical cables and connections need to be electromagnetically shielded. In particular, in the newly growing field of hybrid or electrical vehicles, high power requirements translate into electrical circuits transporting large electrical currents and holding high voltages. Due to the electrical powers involved, shielding of the connectors and cables is an essential need to avoid possible interferences induced by electromagnetic energy. It is of importance to electrically connect the electromagnetic shielding of for example a power cable to the electromagnetic shielding of a housing to establish a shielding continuity. It is also of importance to electrically connect the electromagnetic shielding of a power connector to the electromagnetic shielding of another power connector to establish a shielding continuity. Due to the large demand for electrical components, e.g. in the field of automotive applications, such components have to be efficiently and inexpensively manufactured; however, they still have to fulfill high quality standards.
An example of a typical prior art shielding connection is given in the U.S. Pat. No. 4,547,623. Here, the shielding of a cable is electrically connected to a metallic housing to achieve a shielding continuity in a connector arrangement. To establish the connection, the cable insulation is partially removed and an assembly of different metal rings is arranged around the stripped portion of the cable in electrical contact with the cable shielding.
This ring assembly is in electrical contact with the inner surface of the conductive housing, thereby providing shielding continuity over the connector. In order to provide a more flexible solution, U.S. Pat. No. 5,237,129 proposes to use contact elements in form of torus-shaped spring elements to establish electrical contact between the shielding of a cable and the shielding of a connector housing in which the cable is mounted. These spring elements are positioned inside of a metallic housing at a stripped portion of the cable in electrical contact with the cable shielding. Upon assembly the springs are compressed in axial direction such that they expand in the radial direction thereby pressing against the cable shielding on one side and the inner wall of the metallic housing on the other side. Thus an electric connection between the cable shielding and the metallic housing is established.
The development of such connection elements culminated in sophisticated spring elements as e.g. presented in the very recent publication EP 2 109 201 A2 (published in October 2009). This document discloses a new kind of spring element which can be mounted inside of a metallic housing establishing an electrical connection to the shielding of a cable within a stripped portion of the cable. This new spring element is constructed in a very sophisticated way offering a large range of possible diameters for the cable as well as a large range of possible inner diameters of the housing.
The above described parts are examples of common solutions providing an electrical connection between the shielding of a power cable to an outer connecting element as e.g. the shielding of a connector housing. The solution proposed in document U.S. Pat. No. 4,547,623 constitutes a complicated assembly consisting of many parts. The connecting parts are inflexible metallic rings which have to be fabricated within small tolerances and are therefore only applicable within a special designated assembly. Documents U.S. Pat. No. 5,237,129 and EP 2 109 2010 A2 propose to establish the required connection by using spring elements which are more flexible. However, such elements are complicated in fabrication and expensive. For these reasons, the above described solutions are in particular not optimal for the use in mass production.
One of the aims of the present invention is to provide a new electromagnetic shielding device which minimizes or eliminates the above described problems. These and other objects which become apparent upon reading the following description are solved by an electromagnetic shielding device according to claim 1.